1. Field of the Invention
The present invention relates to a presser device for a sewing machine, which is constructed such that pressing means for pressing and holding workpiece can be automatically brought to a holding position, a releasing position and an intermediate position by the action of drive means.
2. Description of the Prior Art
In Japanese Patent Publication No. 30034/1982 (or Application No. 32766/1975), there is disclosed a presser device for a sewing machine, which is constructed such that a solenoid is energized to bring a presser foot to a releasing position after the end of a sewing operation and is then deenergized to move the presser foot from the releasing position to a holding position when a time required for detaching the workpiece has elapsed. According to this construction, however, the presser foot is arranged only in the releasing position or the holding position but not in any intermediate positions. This is accompanied by a difficulty in positioning the workpiece for a next sewing operation.
In another Japanese Patent Publication No. 15381/1972 (or Application No. 766/1969), there is disclosed a presser device for a sewing machine, which is constructed such that a solenoid can be energized at a predetermined voltage level on the basis of the manual operation of a foot pedal to arrange pressing means in an intermediate position between a holding position and a releasing position thereby to facilitate exactly positioning of the workpiece. In order to effect this arrangement, according to this construction, however, it is necessary to adjust the depression of a foot pedal to a proper level so that the predetermined voltage level may be attained. This raises a problem that a heavy burden is imposed upon the worker who has to continuously sew a numerous sheets of workpiece.